Whyteleafe has some flood risk, and very little of it comes from a river. The village lies in a dry valley. Only a small number of postcodes are in a river flood zone. About a third of postcodes are flagged once rain running off the slopes is counted. Nothing in the record shows the village has ever flooded. The thing to watch here is the rain, since there is no river to worry about.
On the Environment Agency's river and sea mapping, about 3% of the area's postcodes are in flood zone 3, the highest-probability band, and about 1% are in flood zone 2, the medium-probability band outside it. The two bands do not overlap, so zone 2 is smaller here because it is only the outer edge around zone 3. For a village a long way inland in the North Downs, the river and sea map is close to empty.
Surface water is where the risk lies. The Environment Agency's river and sea zones do not measure it at all, and Whyteleafe's geography makes it the measure that matters. A dry valley is dry until heavy rain arrives, and then it collects the water from the slopes on both sides.
The Environment Agency's climate-adjusted mapping puts about 7% of postcodes in the flood zone once its allowance for future rainfall and river flows is added. That is the model's scenario for later decades. It shows where the edge might move. No one has promised it will.
For insurance, a home in one of the few flood-zone postcodes, or one flagged high for surface water, can expect insurers to ask more questions and possibly charge more. The rest of the village should find flood cover routine. Get an insurance quote for the exact address early on, because the insurer checks at postcode level.
Look at every measure together, surface water included, and the picture changes. About 11% of Whyteleafe's postcodes rate high on at least one flood measure, 34% medium and 29% low. These bands include the river zones, so the figures cannot be added to the zone shares above. A postcode only has to fail one test to be flagged. The gap between a near-empty river map and a third of postcodes flagged medium or worse is what this answer is about.
Counting homes is more useful than counting postcodes. In the 18 postcodes that carry any river or sea risk, the Environment Agency's property-level mapping counts 481 properties. Two of them are at high risk, only one of those residential, and 207 are at medium risk. Postcodes with no river or sea risk are left out of that count altogether.
On whether anything stands between the water and the house, the Environment Agency's flood extents put about 3% of postcodes in the high-risk area with defences left out of the model, and about 3% with them included. The defences make no difference to the modelled picture here. Even where a defence does appear in the model, that tells you it exists. It does not tell you the house stays dry.
The nearest tide gauge in the national record is at Portsmouth, where sea level rose by about 2 millimetres a year between 1962 and 2023. The gauge measures the Solent, and Whyteleafe is a long way from it. The sea is the least of the village's water worries.
There is no recorded history of flooding anywhere in the area. That is good news. It also means only that no flood made it into the record.
Whyteleafe's flood risk is average. The river barely registers, and the valley floor needs checking for surface water.